As I've written previously, knowledge of basic linguistic principles should include dialects — both L1 and L2. Learners at the higher levels need to know that they will encounter different dialects as they interact with native speakers.

An understanding of linguistics will enhance one's ability to teach and develop materials for ESL learners. The ACTFL standards encourage the study of how languages work through the use of comparisons.

"Develop insight into the nature of language and culture in order to interact with cultural competence. Language comparisons: Learners use the language to investigate, explain and reflect on the nature of language through comparisons of the language studied and their own. Cultural comparisons: Learners use the language to investigate, explain and reflect on the concept of culture through comparisons of the cultures studied and their own."

Variations in language used by different groups are referred to as dialects, which are mutually intelligible varieties of the same language.

Understanding dialects will help ESL instructors as they deal with the different varieties of English as well as the home languages of their students. Some home languages have dialect forms that vary widely. A strong literary tradition may keep an educated form of the language alive even if the language breaks down into different dialects.

Let's take a look at a few examples.

Arabic

Arabic, for example, has a literary form, called "classical," "modern standard" or "formal" Arabic that coexists with the various regional dialects, called "colloquial" Arabic. An intermediate form, educated standard Arabic, is used when speakers from different regions need to communicate. Standard Arabic developed as a specialized dialect used in pre-Islamic times (the Jahiliyyah) whenever a colloquial dialect could not be employed.

"It is now thought that side by side with the tribal dialects there existed a specialized literary language used as a koine for the intertribal affairs," according to author James T. Monroe.

This special dialect functioned idioms for literature and was understood by everyone; it developed together with the other dialects from which it borrowed extensively, and it had an ordered set of inflections, which made it an ideal vehicle for poetry and rhymed prose.

When Muhammad began to preach the message of Islam, he used this form of speech for the Koran since this linguistic form had a wider appeal than any one of the dialects. Thus, even though spoken Arabic differs from region to region, the literary language has remained basically unchanged (Perry, 1997).

Unlike the Bible, the Koran was not allowed to be translated, except for the official translation into Turkish after the Ataturk revolution. This dichotomy is referred to as diglossia. Grammarians often work to keep the "Standard" form pure.

"The Moslem Arabic grammarians in the eighth and ninth centuries A.D. working at Basra attempted to purify Arabic in order to restore it to the perfection of the Koran Arabic," wrote Victoria Fromkin and Robert Rodman.

In the case of classical Arabic, the Koran preserved the language for each generation as the Koran was taught in the Islamic schools and mosques and often memorized by faithful Muslims. Even non-Arabs learned the classical form so they could read the Koran and the Hadith (Tradition of the Prophet).

Modern standard Arabic — Fushaa (most eloquent) or Nahawii (grammatical) — is based on classical Arabic and is the language of instruction in schools and the language of government, newspapers, broadcasting and literature. Spoken Arabic — called 'aami or daarij (colloquial) — is the common language of a particular region like Morocco, for example. Even though there is wide variation among the dialects, they share a common root and are not considered separate languages.

"In some cases, political concerns may result in dialects being considered separate languages. Political, ethnic, religious, literary or other identities force a division where linguistically there is relatively little difference — Hindi vs. Urdu, Bengali vs. Assamese, Serbian vs. Croatian, Twi vs. Fanti, Xhosa vs. Zulu," according to Fromkin et al.

Chinese

Sometimes the opposite happens — when the spoken varieties are so far apart that they are mutually unintelligible. Only a common written language keeps the people unified.

"Chinese is a case where linguistic criteria alone are in conflict with each other," according to Fromkin et al. "From the viewpoint of the spoken language, the many hundreds of dialects in China can be grouped into eight main types, which are mutually unintelligible to various degrees.

"But speakers of all these dialects share the same written language tradition, and those who have leaned the system of Chinese characters are able to communicate with each other. Despite the linguistic differences, therefore, Chinese is considered by its speakers to be a single language."

Also in China, one form of Mandarin has become the "common language." The outcome of this top-down linguistic planning depends on several factors.

"Much will depend on how flexibly the authorities interpret the notion of standard, and whether they are able to achieve a balance between the competing pressures of respecting popular usage (where there is a strong case for variety) and the need for national communication (which could lead to a form of centralized laying down of prescriptive linguistic rules)," David Crystal writes.

Schools are an important factor when nations attempt to adopt a common language or a dialect of the home language, as was the case with Parisian French and Tokyo Japanese.

U.S. Hispanic

Some students may use a variety of L1 that is significantly different that what is spoken in their home country. As Fox News explains:

"Iris Huerta was born in Guadalajara, Mexico but was raised in East Los Angeles. When she was in high school, her family moved to a neighborhood where the Latina became a minority. Then an AP English student, Huerta was surprised when she had to convince her new school that she was fluent in English.

"They made me take a standardized test and a listening test, she recalled. 'They straight out told me if you hadn't told us you spoke Spanish at home you wouldn't have to take the test.'

"Educators are increasingly concerned about Latino students like Huerta. Some don't speak Spanish but use a dialect from Latino neighborhoods in areas such as Los Angeles, New York, Miami and Houston. Their speech rings with traces of Spanish accents, rhythm and grammar."